Alignment Key 

Definition

Determines where floats are in the standard sequence or a parallel sequences.

Use

If several sequences in a routing are to be carried out in parallel, the lead times of these sequences generally differ. As a result, floats occur within the sequences. These floats can be either at the start of the end of a sequence. The alignment key determines where a possible float is in a sequence.

·         If the sequence is aligned with the earliest date, the float is at the finish of the sequence.

·         If the sequence is aligned with the latest date, the float is at the start of the sequence.

Integration

An alignment key is assigned to the standard sequence and to each of the parallel sequences. The following graphic shows the relationship between the alignment key and how sequences are scheduled. The floats are hatched in the graphic. Although the parallel sequences A and B are aligned to the earliest possible data, the standard sequence has an alignment key, that aligns the sequence to the latest possible dates.

The alignment key is valid for all of the sections in the standard sequence for which there are parallel sequences.

In the above example this is true for operations 20 and 30 as well as operation 50 in the standard sequence.